A study of variation in wood-decay ability among isolates of Coniophora puteana (Schum. ex Fr.) Karst

McPhee, Alistair Barlow (1978) A study of variation in wood-decay ability among isolates of Coniophora puteana (Schum. ex Fr.) Karst. PhD thesis, University of Glasgow.

Abstract

An investigation was carried out to examine the variation in decay potential existing among a range of isolates of the brown-rotting basidiomycete Coniophora puteana. Consideration was given to possible factors which might contribute to such differences. Levels of decay of Pinus sylvestris sapwood test-pieces, produced by 37 isolates of C. puteana, were measured after 10 weeks incubation under controlled conditions. Decay was assessed by measuring the percentage weight losses and the cross-grain breaking strengths of the wood test-pieces. A wide variation in decay-potential was found among the isolates tested, and it was possible to identify two distinct populations; namely, one which produced high levels of decay, and another which showed low decay-potential. Rates of radial growth on agar were measured, and it was found that these varied substantially between strains. These variations did not, however, show a consistent correlation with decay-potential. There was also variation in the influence of temperature on growth by three representative strains. The extracellular cellulase activities of a number of isolates were measured after growing them in static liquid culture on native cellulose and on sodium carboxymethylcellulose (a soluble substituted form of cellulose) . Carboxymethylcellulose (a soluble Substit-uted form of cellulose).carboxymethylcellulase (cx), c1 (see reese et al., 1950),and cellobiase activities were assayed in the culture filtrates. There was little variation in either cx or c1 activities, and it did not correlate with the decay-potential variation; there was no detectable cellobiase activity. Activity was not present in filtrates from cultures grown on sodium carboxymethylcellulose, but was present in those from cultures grown on cotton wool, so it appears to be induced. Conversely, Cx activity was present in both sets of culture filtrate. A partial separation of the components of the cellulqse complex, was carried out by gel filtration on Sephadex G-75; two Cx enzymes were identified, with approximate molecular weights of 32000 and less than 10000. The filtrates from a number of isolates were further analysed by polyacrylamide gel electrophoresis, and it was found that the cell-free protein profile will vary in accordance with the substrate used to grow the fungus; strain differences were also indicated. The effect which different concentrations of the two wood preservatives pentachlorophenol (PCP) and tri-n-butyl tin oxide (TBTO), exert on growth by a range of isolates of C. puteana, was examined. A diversity of response to low concentrations of both fungicides was found.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: S A Hutchinson
• Keywords: Plant pathology, Microbiology
• Date of Award: 1978
• Depositing User: Enlighten Team
• Unique ID: glathesis:1978-73421
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 14 Jun 2019 08:56
• URI: https://theses.gla.ac.uk/id/eprint/73421